1. Field of the Invention
One embodiment of the invention disclosed herein relates to power supply circuits.
2. Description of the Related Art
In some cases, it is necessary to input negative voltage in a liquid crystal display device, a CCD, a digital camera, or the like. As a circuit for supplying such negative voltage, inverting DCDC converter circuits have been known (see Patent Document 1).
In Patent Document 1, a feedback voltage VFB which is negative voltage is generated using a power source voltage VDD and a ground voltage GND (0 V).
The feedback voltage VFB which is negative voltage is converted into positive voltage by a negative-to-positive voltage conversion circuit. Accordingly, the feedback voltage VFB which is negative voltage is detected by the negative-to-positive voltage conversion circuit.